Effect of low frequency phonons on structural properties of ZIFs with SOD topology

Filip Formalik (1) , Michael Fischer , Justyna Rogacka (1) , Lucyna Firlej (1) , Bogdan Kuchta

1 L2C - Laboratoire Charles Coulomb

The structural transformations of periodic structures are very often initiated by the dynamicalfluctuation of theequilibrium structure. The natural mechanical excitations in crystals are called phonons. If the energy of thesefluctuations is low, they can easily be transformed into static deformations which define new structural prop-erties of the materials. This is the case in so called gate opening transformations which modify the structure andthe adsorptive properties of porous solids. Using the example of three SOD-type zeolitic imidazolate frameworks(ZIFs) containing linker molecules with different substituents, we show that analysis of low-frequency phononsobtained from density-functional theory (DFT) calculations allows one to model the observed gate opening andto understand the microscopic mechanism of this structural transformation.

Mots clés: ZIF; Soft mode; Phonon; Gate-opening; MOF

Domaines: Physique Numérique [physics.comp-ph]; Science des matériaux [cond-mat.mtrl-sci]

Filip Formalik, Michael Fischer, Justyna Rogacka, Lucyna Firlej, Bogdan Kuchta. Effect of low frequency phonons on structural properties of ZIFs with SOD topology. Microporous and Mesoporous Materials, 2020, 304, pp.109132. ⟨10.1016/j.micromeso.2018.09.033⟩. ⟨hal-02116566⟩